Lithium ion-conducting solid materials

Abstract

Described are a solid material which has ionic conductivity for lithium ions, a process for preparing said solid material, a use of said solid material as a solid electrolyte for an electrochemical cell, a solid structure selected from the group consisting of a cathode, an anode and a separator for an electrochemical cell comprising the solid material, and an electrochemical cell comprising such solid structure.

1 . A solid material having a composition according to formula (IIc)
   Li 6+m P 1-3n M1 (z1)+   n M2 (z2)+   n M3 (z3)+   n Y 5 X  (IIc)
   wherein   X is selected from F, Cl, Br and I,   Y is selected from O, S, Se and Te,   M1 (z1)+  to M3 (z3)+  are selected from the group consisting of Si 4+ , Ge 4+ , Sn 4+  and Sb 5+ ,   n is a number in the range of from 0.05 to 0.3,   and m=5−[5*(1−x)+n*(z1+z2+z3)].   
     
     
         2 . The solid material according to  claim 1 , wherein X is I or Y is S. 
     
     
         3 . The solid material according to  claim 1 , wherein X is I and Y is S. 
     
     
         4 . The solid material according to  claim 1 , wherein n is a number in the range of from 0.2 to 0.28. 
     
     
         5 . The solid material according to  claim 1 , wherein M1 (z1)+  is Si 4+ , M2 (z2)+  is Ge 4+ , and M3 (z3)+  is Sb 5+ , X is I (iodine) and Y is S. 
     
     
         6 . The solid material according to  claim 1 , wherein the material comprises a crystalline phase having an argyrodite structure. 
     
     
         7 . A process for preparing a solid material according to  claim 1 , comprising:
 (a) providing a reaction mixture comprising the precursors
 (1) one or more of oxide, sulfide, selenide and telluride of lithium, 
 (2) one or more of oxide, sulfide, selenide and telluride of phosphorous, 
 (3) one or more compound LiX wherein X is selected from F, Cl, Br and I, 
 (4) compounds selected from the group consisting of oxides, sulfides, selenides and tellurides of three cations selected from the group consisting of, Si 4+ , Ge 4+ , Sn 4+ , and Sb 5+ , 
 (5) optionally one or more of S, Se and Te in elemental form, 
 wherein in the reaction mixture the molar ratio of all elements is selected so that it matches formula (IIc); and 
   (b) reacting the precursors to obtain a solid material having a composition according to formula (IIc).   
     
     
         8 . The process according to  claim 7 , wherein in step (a)
 the precursor (1) is Li 2 S, and/or   the precursor (2) is P 2 S 5 , and/or   the precursor (3) is LiI, and/or   the precursor (4) is selected from the group consisting of SiS 2 , GeS 2 , SnS 2  and Sb 2 S 3 , and/or   the precursor (5) is elemental sulphur or is not present.   
     
     
         9 . The process according to  claim 7 , wherein in step (a)
 the precursor (1) consists of Li 2 S,   the precursor (2) consists of P 2 S 5 ,   the precursor (3) consists of LiI,   the precursor (4) consists of SiS 2 , GeS 2 , and Sb 2 S 3 ,   the precursor (5) consist of elemental sulfur or is not present.   
     
     
         10 . The process according to  claim 7 , comprising:
 (a) preparing or providing a solid reaction mixture comprising the precursors as defined in  claim 7 ; and   (b1) heat-treating the reaction mixture in a temperature range of from 200° C. to 600° C. for a total duration of 1 to 48 hours or more so that a reaction product is formed and cooling the reaction product so that a solid material having a composition according to formula (IIc) is obtained.   
     
     
         11 . The process according to  claim 7 , comprising:
 (a) preparing or providing a solid reaction mixture comprising the precursors as defined in  claim 7 ; and   (b2) mechanochemical treatment of the solid reaction mixture so that a solid material having a composition according to formula (IIc) is obtained.   
     
     
         12 . The process according to  claim 11 , further comprising
 (c) annealing the solid material obtained by mechanochemical treatment in a temperature range of from 200° C. to 600° C. for a total duration of 1 to 48 hours and cooling the annealed solid material.   
     
     
         13 . A solid structure for an electrochemical cell, wherein the solid structure is selected from the group consisting of cathode, anode and separator, wherein the solid structure for an electrochemical cell comprises a solid material according to  claim 1 . 
     
     
         14 . An electrochemical cell comprising a solid material according to  claim 1 . 
     
     
         15 . The electrochemical cell according to  claim 14 , wherein the solid material is a component of a solid structure selected from the group consisting of cathode, anode and separator.